Internet connects can handle a wide array of different types of data traffic. Some Internet traffic, such as e-mail and web browsing, can be handled on a “best effort” basis because such traffic can tolerate a substantial amount of latency, jitter and relatively low throughput without adversely affecting the end user's overall experience. Other types of Internet traffic, such as Voice over IP (VoIP) and MPEG video over IP, require an assured rate of throughput as such traffic is adversely affected by jitter and latency. That is, VoIP and MPEG video over IP have relatively strict requirements for latency, jitter and throughput. Such requirements frequently cannot be met on a best effort basis.
The baseline Internet Protocol (IP) does not provide any guarantees as to Quality of Service (QoS). However, various other protocols have been developed that can be used to ensure that a data flow obtains a specific QoS requirement.
The Data-over-Cable Service Interface Specification (DOCSIS) and the PacketCable Multimedia specification provide mechanisms whereby packets can be classified and divided into data flows, called “service flows”. Each service flow can be given a specific QoS guarantee. Thus, for example, packets generated in a VoIP session can be directed to a specific service flow having the precise bandwidth, latency and jitter guarantees needed for a call, while other traffic (such as e-mail and web browsing) can be handled on a best effort basis and directed into a generic service flow, which typically does not have any service guarantees.